Abstract
Human glial fibrillary acidic protein-delta (GFAP-delta) is a GFAP protein isoform that is encoded by an alternative splice variant of the GFAP-gene. As a result, GFAP-delta protein differs from the predominant splice form, GFAP-alpha, by its C-terminal protein sequence. In this study, we show that GFAP-delta protein is not expressed by all GFAP-expressing astrocytes but specifically by a subpopulation located in the subpial zone of the cerebral cortex, the subgranular zone of the hippocampus, and, most intensely, by a ribbon of astrocytes following the ependymal layer of the cerebral ventricles. Therefore, at least in the sub ventricular zone (SVZ), GFAP-delta specifically marks the population of astrocytes that contain the neural stem cells in the adult human brain. Interestingly, the SVZ astrocytes actively splice GFAP-delta transcripts, in contrast to astrocytes adjacent to this layer. Furthermore, we show that GFAP-delta protein, unlike GFAP-alpha, is not upregulated in astrogliosis. Our data therefore indicate a different functional role for GFAP-delta in astrocyte physiology. Finally, transfection studies showed that GFAP-delta protein expression has a negative effect on GFAP filament formation, and therefore could be important for modulating intermediate filament cytoskeletal properties, possibly facilitating astrocyte motility. Further studies on GFAP-delta and the cells that express it are important for gaining insights into its function during differentiation, migration and during health and disease.
Original language | English |
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Pages (from-to) | 289-300 |
Number of pages | 12 |
Journal | GLIA |
Volume | 52 |
Issue number | 4 |
DOIs | |
Publication status | Published - Dec 2005 |
Keywords
- Alternative Splicing
- Astrocytes
- Brain
- Cell Differentiation
- Cell Line, Tumor
- Cell Proliferation
- Cerebral Cortex
- Cytoskeleton
- Ependyma
- Glial Fibrillary Acidic Protein
- Hippocampus
- Humans
- Intermediate Filament Proteins
- Lateral Ventricles
- Pia Mater
- Protein Isoforms
- Protein Structure, Tertiary
- RNA, Messenger
- Stem Cells
- Journal Article
- Research Support, Non-U.S. Gov't